Cardiac surgery in Iran has been associated with different facilities, equipment and patient populations in comparison to countries from which most of the academic papers used for identification of risk factors related to outcome and subsequent establishment of risk stratification models originate from. During a 15-month period all patients admitted for adult cardiac surgery using cardiopulmonary bypass (CBP) in a university affiliated teaching hospital were enrolled in a prospective study. Appropriate statistical tests were used to analyze data for mortality and morbidity. There were 730 adults (63% male, 37% female), with age ranged from 16 to 82 (mean, 51.4 +/- 14.4). A mortality rate of 5.3% and morbidity of 14.8% (major + minor) were observed in the whole group. Factors correlated with mortality were: age (p = 0.019), emergency surgery (p < 0.0001), redo cardiac surgery (p = 0.01), left ventricular (LV) aneurysm (p < 0.001), presence of catastrophic states (p < 0.001), low ejection fraction (p = 0.04), history of hypertension (p = 0.05), the individual surgeon (p < 0.0001), and CPB duration (p < 0.0001). Factors affecting morbidity included: female gender (p = 0.04), age (p = 0.03), emergency surgery (p = 0.001), redo surgery (p = 0.008), and catastrophic states (p < 0.001). The mortality in our study group may be compared with reports presented in the literature. Factors such as age, emergency surgery, redo cardiac surgery, and catastrophic states are statistically related to both mortality and morbidity.